Our studies are intended to clarify some of the mechanisms that operate in tumor metastasis. We are investigating the role of membrane-associated components of tumors, including tumor associated antigens, tumor specific antigens and tumor specific transplantation antigens. We are also investigating the role of specific anti-tumor antibodies and of tumor specific immune complexes. We are studying the interactions between these membrane-associated and humoral components and the various immunocompetent cells involved in the immune response to tumors. Such studies have the ultimate objective of providing new information that can be applied to the prevention or cure of metastatic disease. For these purposes we are employing a relevant animal model -chemically induced, transplantable rat mammary carcinomas, both metastatic and nonmetastatic. In initial studies we have identified and quantitated a common organ specific tumor associated antigen, apparently characteristic of our metastatic tumors. This antigen is shed by the tumors and may be functionally involved in the metastatic process. The components of interest are being identified and isolated by specific methods which include the use of immunoadsorbents, lectin affinity adsorbents and xenogeneic antibodies specific for the various membrane-associated components. Sensitive and specific radioimmunoassays are being developed to quantitate these components. Similar sensitive assays are being developed to both detect and quantitate specific anti-tumor antibodies and the specific immune complexes. A prime objective of these studies is to determine how, and to what extent, the various immunologically defined components are involved in the metastatic process. A second objective is to use the specific analytical procedures we are developing in the animal system as guides in developing procedures for early detection of human tumors.